Caudal migration of endoprostheses after treatment of abdominal aortic aneurysms

Background. The purpose of this study is to assess the migration of endoprostheses 2 years after endovascular abdominal aortic aneurysm repair. Methods. Ten patients underwent placement of bifurcated endoprostheses for infrarenal aneurysm and had 2-year CT follow-up. Standardized contrast-enhanced CT with 1.5- or 2-mm overlapping slice thickness was used. Four independent observers measured the distance from the lowest renal artery to the craniad end of the graft. Results. As a whole, the endoprostheses migrated an average of 2.7 ± 2.6 mm caudad at 24 months compared with baseline (P < 0.001). Four patients (40%) experienced ≥3-mm migration of the endoprostheses. On review of the 6- and 12-month follow-up CT scans, movement occurred at both the first- and the second-year intervals. Conclusions. Endovascular stent-grafts frequently migrate away from the renal arteries. This may be due to natural elongation of the native infrarenal aortic segment, but could also result from inadequate attachment of the proximal stent-graft. Although there have been no adverse clinical events in this group, continued close follow-up is mandatory following endovascular aneurysm repair.